NEW BRUNSWICK, N.J. (CBSNewYork) – The number of people diagnosed with lyme disease is the highest it’s been in two decades, according to the New Jersey Department of Health.

Alvaro Toledo, an assistant professor at Rutgers University, said there were a few reasons for the increase, reports CBSN New York’s Meg Baker.

In 2017 there were more than 5,000 cases reported of lyme disease in the due to more awareness about the disease, more accurate testing than in years past and changes in New Jersey’s environment with high humidity across the landscape.

“The tick population is also dependent on weather conditions and also the presence of animals to feed on,” said New Jersey state epidemiologist Dr. Christina Tan.

Toledo says the black legged tick or deer tick is attracted to wooded and grassy areas. The specific tick that carries lyme disease uses deer and rodents as hosts to breed.

The Garden State just happens to have a large population of both. Tan notes the top counties with infections are the more heavily wooded Warren County, Hunterdon County, Sussex County and Morris County.

Quest Diagnostics has released their findings of over six million blood tests taken over the last seven years. The New Jersey-based clinical laboratory says cases of Lyme have exploded in unusual areas like California and Florida.

Lab workers believe ticks are finding it easier to survive in new regions and spreading diseases to unsuspecting residents.